Grit Classifier: Innovative Practice of Shaftless Spiral Sand and Water Separation Technology

In the sewage treatment process, the grit classifier is one of the equipment to ensure the stable operation of the subsequent treatment equipment. As a light sand and water separation equipment, the WSF shaftless spiral sand and water separator has become a key link in the domestic sewage treatment project with its high-efficiency separation and low maintenance cost.

The core of the WSF grit classifier lies in dynamic separation and gradient dehydration. After the sand and water mixture enters the separation tank through the feed port, the sand settles to the bottom of the tank under the action of gravity, and the separated clean water is discharged through the overflow weir and enters the next treatment unit. At this time, the shaftless spiral shaft rotates at a low speed, pushing the deposited sand upward along the U-shaped groove. In this process, the spiral blades and the flexible wear-resistant lining at the bottom of the groove form an extrusion space, and the sand is dehydrated twice under the action of mechanical push and self-weight, and the water content of the sand at the final discharge port can be controlled within 60%.

The guide plate designed inside the separation tank further optimizes the flow distribution. The guide plate divides the mixed liquid into two layers: the upper layer with low concentration of water flows quickly, while the lower layer with high concentration of sand is concentrated in the spiral conveying path. The core innovation of the WSF type equipment lies in the shaftless screw transmission. Compared with the traditional shafted screw, the shaftless design reduces the wear of the central shaft and reduces the jamming caused by the entanglement of sand particles.